Paroxysmal atrial fibrillation ablation with a novel temperature-controlled CF-sensing catheter: Q-FFICIENCY clinical and healthcare utilization benefits

INTRODUCTION

The prospective, nonrandomized, multicenter Q-FFICIENCY study demonstrated the safety and 12-month efficacy of paroxysmal atrial fibrillation (AF) ablation with the novel QDOT MICRO temperature-controlled, contact force-sensing, radiofrequency (RF) catheter. Participants underwent pulmonary vein isolation with very high-power short-duration (vHPSD) mode (90 W, ≤4 s) alone or combined with conventional-power temperature-controlled (CPTC) mode (25-50 W). This study aimed to assess quality-of-life (QOL) and healthcare utilization (HCU) benefits experienced by Q-FFICIENCY study participants.

METHODS

Besides evaluating procedural efficiency, QOL and HCU were assessed through 12 months postablation via Atrial Fibrillation Effect on Quality-of-Life Tool (AFEQT) score, antiarrhythmic drug (AAD) use, and incidence of cardioversion and cardiovascular hospitalization.

RESULTS

Of 191 participants enrolled, 166 were ablated with the new catheter. Compared to baseline, statistically significant, clinically meaningful improvements in composite and subcategories of AFEQT scores were observed at 3 months and sustained through 12 months (12-month increase, 29.3-44.2 points). Class I/III AAD use decreased from 97.6% (162/166) at baseline to 19.6% (31/158) during Months 6-12, representing a significant 79.9% reduction. The cardioversion rate significantly declined by 93.9% from 31.3% (12 months preablation) to 1.9% (evaluation period). One-year Kaplan-Meier estimates of freedom from all-cause and cardiovascular hospitalization were 80.9% (95% confidence interval [CI], 74.8%-86.9%) and 88.8% (95% CI, 84.0%-93.7%), respectively.

CONCLUSIONS

Paroxysmal AF ablation with the novel temperature-controlled RF catheter in vHPSD mode, alone or with CPTC mode, led to clinically meaningful improvement in QOL and significant reduction in AAD use, cardioversion, and cardiovascular hospitalization.

Performance of the REAL-AF Same-Day Discharge Protocol in Patients Undergoing Catheter Ablation of Atrial Fibrillation

BACKGROUND

Same-day discharge (SDD) after catheter ablation of atrial fibrillation (AF) has been widely adopted. Nevertheless, planned SDD has been performed by using subjective criteria rather than standardized protocols.

OBJECTIVES

The goal of this study was to determine the efficacy and safety of the previously described SDD protocol in a prospective multicenter study.

METHODS

Using the REAL-AF (Real-world Experience of Catheter Ablation for the Treatment of Paroxysmal and Persistent Atrial Fibrillation) SDD protocol eligibility criteria (stable anticoagulation, no bleeding history, left ventricular ejection fraction >40%, no pulmonary disease, no procedures within 60 days, and body mass index <35 kg/m2), operators prospectively determined whether patients undergoing ablation of AF were candidates for SDD (SDD vs non-SDD groups). Successful SDD was achieved if the patient met the protocol discharge criteria. The primary efficacy endpoint was the success rate of SDD. The primary safety endpoints were readmission rates as well as acute and subacute complications. The secondary endpoints included procedural characteristics and freedom from all-atrial arrhythmias.

RESULTS

A total of 2,332 patients were included. The REAL-AF SDD protocol identified 1,982 (85%) patients as potential candidates for SDD. The primary efficacy endpoint was achieved in 1,707 (86.1%) patients. The readmission rate for SDD vs non-SDD group was similar (0.8% vs 0.9%; P = 0.924). The SDD group had a lower acute complication rate than the non-SDD group (0.8% vs 2.9%; P < 0.001), and there was no difference in the subacute complication rate between groups (P = 0.513). Freedom from all-atrial arrhythmias was comparable between groups (P = 0.212).

CONCLUSIONS

In this large, multicenter prospective registry, the use of a standardized protocol showed the safety of SDD after catheter ablation of paroxysmal and persistent AF. (Real-world Experience of Catheter Ablation for the Treatment of Paroxysmal and Persistent Atrial Fibrillation [REAL-AF]; NCT04088071).

Very High-Power Short-Duration, Temperature-Controlled Radiofrequency Ablation in Paroxysmal Atrial Fibrillation: The Prospective Multicenter Q-FFICIENCY Trial

BACKGROUND

QDOT MICRO (QDM) is a novel contact force-sensing catheter optimized for temperature-controlled radiofrequency (RF) ablation. The very high-power short-duration (vHPSD) algorithm modulates power, maintaining target temperature during 90 W ablations for ≤4 seconds.

OBJECTIVES

This study aims to evaluate safety and 12-month effectiveness of the QDM catheter in paroxysmal atrial fibrillation (AF) ablation using the vHPSD mode combined with conventional-power temperature-controlled (CPTC) mode.

METHODS

In this prospective, multicenter, nonrandomized study, patients with drug-refractory, symptomatic paroxysmal AF underwent pulmonary vein (PV) isolation with QDM catheter with vHPSD as primary ablation mode, with optional use of the CPTC mode (25 to 50 W) for PV touch-up or non-PV ablation. The primary safety endpoint was incidence of primary adverse events within ≤7 days of ablation. The primary effectiveness endpoint was freedom from documented atrial tachyarrhythmia recurrence and acute procedural, repeat ablation, and antiarrhythmic drug failure.

RESULTS

Of 191 enrolled participants, 166 had the catheter inserted, received RF ablation, and met eligibility criteria. Median procedural, RF application for ablating PVs, and fluoroscopy times were 132.0, 8.0, and 9.1 minutes, respectively. The primary adverse event rate was 3.6%. Imaging conducted in a subset of participants (n = 40) at 3 months did not show moderate or severe PV stenosis. The Kaplan-Meier estimated 12-month rate for primary effectiveness success was 76.7%; freedom from atrial tachyarrhythmia recurrence was 82.1%; clinical success (freedom from symptomatic recurrence) was 86.0%; and freedom from repeat ablation was 92.1%.

CONCLUSIONS

Temperature-controlled paroxysmal AF ablation with the novel QDM catheter in vHPSD mode (90 W, ≤4 seconds), alone or with CPTC mode (25 to 50 W), is highly efficient and effective without compromising safety. (Evaluation of QDOT MICRO Catheter for Pulmonary Vein Isolation in Subjects With Paroxysmal Atrial Fibrillation [Q-FFICIENCY]; NCT03775512.).

Safety and effectiveness of near-zero fluoroscopy paroxysmal AF radiofrequency ablation with a temperature-controlled, contact force-sensing catheter: a Q-FFICIENCY study sub-analysis

Background/Introduction

Q-FFICIENCY evaluated 12-month (M) safety and efficacy of temperature-controlled paroxysmal atrial fibrillation ablation with a novel contact force-sensing, radiofrequency catheter with 3 microelectrodes and 6 thermocouples. Patients underwent pulmonary vein isolation with very high-power short-duration (vHPSD; 90 W/ up to 4 s) mode in combination with conventional-power temperature-controlled (CPTC; 25–50 W) mode.

Purpose

To assess procedural efficiency, safety, and 12M outcomes of participants ablated under near-zero fluoroscopy guidance compared to procedures performed with standard fluoroscopy.

Methods

In this US multi-centre (22 sites), non-randomised investigational study, patients underwent pulmonary vein isolation with vHPSD as primary ablation mode; CPTC was used for PV touch-up or non-PV ablation. Primary safety endpoint was incidence of primary adverse events ≤7 days post-procedure. Primary effectiveness was freedom from documented atrial tachyarrhythmia recurrence and additional pre-defined failure modes (acute failure, repeat ablation, new/higher dose anti-arrhythmic drug). Participants were followed-up through 12M post-ablation (3M blanking & 9M evaluation) to assess safety, effectiveness, and healthcare utilisation.

Results

Of 191 participants enrolled (63.5±10.7 years, CHA2DS2-VASc 2.4±1.5, 60.7% men), 166 were ablated with the investigational catheter, and 165 had fluoroscopy data available for inclusion in this analysis. Forty-four participants received ≤1 minute of fluoroscopy. Compared to the &gt;1-minute of fluoroscopy cohort, the ≤1-minute group showed improved efficiencies in all procedural parameters (Table). Primary adverse event rates were similar among groups (≤1-minute, 4.5%; &gt;1-minute, 3.3%). Kaplan-Meier estimated 12M clinical success rates (i.e., freedom from documented symptomatic recurrence) were similar regardless of fluoroscopy exposure (≤1-minute, 85.4%; &gt;1-minute, 86.0%). Freedom from cardiovascular hospitalisation 12M post-ablation was comparable among groups (90.8% vs 88.0%).

Conclusion

Near-zero fluoroscopy paroxysmal atrial fibrillation ablation with the novel temperature-controlled catheter in vHPSD mode, alone or combined with CPTC, led to enhanced procedural efficiencies with good effectiveness and clinical success without comprising safety.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Biosense Webster, Inc.

"Retained wire femoral lead removal and fibroplasty" for obtaining venous access in patients with refractory venous obstruction

BACKGROUND

Patients with wire and catheter refractory venous occlusion are traditionally referred for pectoral transvenous lead extraction (TLE) to obtain venous access. TLE causes 1-2 mm circumferential mechanical or laser destruction of tissue surrounding the lead(s). This not only exposes the patient to the risk of major complications but also can damage nontargeted leads. We present a series of patients where retained wire femoral lead removal and fibroplasty was used to obtain venous access in patients with refractory obstruction.

METHODS

Between 2008 and 2021, we identified 17 patients where retained wire lead removal followed by fibroplasty was used to retain venous access. Demographic and procedural data were obtained by retrospective review of patient charts.

RESULTS

We were able to successfully obtain venous access in all 17 patients in whom this technique was attempted. In two patients the target lead was less than or equal to 1 year old. In the remaining 15 patients, the average dwell time of the target lead(s) was 6 years. There were no procedure-related complications, and no changes in the parameters of other leads were noted.

CONCLUSION

Retained wire femoral lead removal and fibroplasty is safe and highly efficacious at obtaining venous access in patients with refractory venous occlusion. If the target lead(s) is less than or equal to 1 year old, this technique can help obtain venous access at the time of the initial surgery, hence avoiding the need for TLE. Furthermore, in patients referred for TLE to obtain venous access, this technique by avoiding the use of TLE tools spares the patient of the associated risks.

A prospective multi-site registry of real-world experience of catheter ablation for treatment of symptomatic paroxysmal and persistent atrial fibrillation (Real-AF): design and objectives

Purpose

Catheter ablation has become a mainstay therapy for atrial fibrillation (AF) with rapid innovation over the past decade. Variability in ablation techniques may impact efficiency, safety, and efficacy; and the ideal strategy is unknown. Real-world evidence assessing the impact of procedural variations across multiple operators may provide insight into these questions. The Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal (PAF) and Persistent (PsAF) Atrial Fibrillation registry (Real-AF) is a multicenter prospective registry that will enroll patients at high volume centers, including academic institutions and private practices, with operators performing ablations primarily with low fluoroscopy when possible. The study will also evaluate the contribution of advent in technologies and workflows to real-world clinical outcomes.

Methods

Patients presenting at participating centers are screened for enrollment. Data are collected at the time of procedure, 10–12 weeks, and 12 months post procedure and include patient and detailed procedural characteristics, with short and long-term outcomes. Arrhythmia recurrences are monitored through standard of care practice which includes continuous rhythm monitoring at 6 and 12 months, event monitors as needed for routine care or symptoms suggestive of recurrence, EKG performed at every visit, and interrogation of implanted device or ILR when applicable.

Results

Enrollment began in January 2018 with a single site. Additional sites began enrollment in October 2019. Through May 2021, 1,243 patients underwent 1,269 procedures at 13 institutions. Our goal is to enroll 4000 patients.

Discussion

Real-AF’s multiple data sources and detailed procedural information, emphasis on high volume operators, inclusion of low fluoroscopy operators, and use of rigorous standardized follow-up methodology allow systematic documentation of clinical outcomes associated with changes in ablation workflow and technologies over time. Timely data sharing may enable real-time quality improvements in patient care and delivery.

Trial registration

Clinicaltrials.gov: NCT04088071 (registration date: September 12, 2019)

Supplementary Information

The online version contains supplementary material available at 10.1007/s10840-021-01031-w.

Convergence of Epicardial and Endocardial RF Ablation for the Treatment of Symptomatic Persistent AF (CONVERGE Trial): Rationale and design

Atrial fibrillation is the most common sustained arrhythmia affecting over 33 million people worldwide. Approximately 70% of AF patients have non-paroxysmal AF. As AF progresses from paroxysmal to non-paroxysmal forms, the prevalence of comorbidities increases. The efficacy of catheter ablation for persistent and long standing persistent (LSP) AF is <40%, often requiring multiple ablation procedures with greater cost and potentially more complications. There is an unmet need to effectively treat such patients. METHODS: CONVERGE is an investigational device exempt, prospective, multi-center, open label 2:1 randomized controlled pivotal study to evaluate the overall success of the Convergent hybrid procedure compared to endocardial catheter ablation for the treatment of symptomatic persistent AF refractory or intolerant to at least one Class I and /or III anti-arrhythmic drug (AAD). A total of 153 subjects at 27 centers are treated in the study. The CONVERGE study is differentiated from other studies currently being conducted on the persistent AF population, because a) there is no time restriction on the duration of diagnosed AF in the patients being studied and b) the trial allows patients with left atrial sizes up to 6 centimeters. The ongoing trials are limited to either 6 months, 12 months or 3-years of continuous AF making CONVERGE the only ablation trial thus far to include a substantial portion of patients with longstanding persistent AF. The convergent procedure involves combination of minimally invasive pericardioscopic epicardial ablation with endocardial left atrial ablation. The primary endpoint is freedom from AF/AFL/AF absent class I/III AAD, except for a previously failed class I/ III AAD with no increase in dosage following 3-months through 12-months. The primary safety endpoint is the incidence of major adverse events from the procedure through 30-days post procedure. CONCLUSION: CONVERGE AF compares the overall success of the Convergent hybrid procedure to endocardial catheter ablation for the treatment of persistent and longstanding persistent AF. By providing objective comparative data, the study aims to provide guidance on the treatment of such patients.

Risk in the "Red Zone": Outcomes for Children Admitted to Ebola Holding Units in Sierra Leone Without Ebola Virus Disease

We collected data on 1054 children admitted to Ebola Holding Units in Sierra Leone and describe outcomes of 697/1054 children testing negative for Ebola virus disease (EVD) and accompanying caregivers. Case-fatality was 9%; 3/630 (0.5%) children discharged testing negative were readmitted EVD-positive. Nosocomial EVD transmission risk may be lower than feared.